1. Field of the Invention
The present invention relates generally to implantable medical devices, and more particularly, to a drug release capsule for implantation into an accessible lumen of an implantable medical device.
2. Related Art
Medical devices having one or more partially or completely implantable components, generally referred to as implantable medical devices, have provided a wide range of therapeutic benefits to patients over recent decades. One type of implantable medical device that has provided substantial benefits to patients over the years is a prosthetic hearing device. Prosthetic hearing devices process ambient sound to provide hearing ability to a hearing impaired patient.
Prosthetic hearing devices include a category of implantable devices known as cochlear™ implants (also referred to as cochlear™ devices, cochlear™ implant devices, and the like; “cochlear implants” herein). (COCHLEAR is a trademark of Cochlear Limited, Lane Cove, NSW, Australia.) Cochlear implants include an array of stimulation electrodes which is implanted in the cochlea of the patient (referred to herein as a recipient). The electrode array is controlled by an electronic system encased in a hermetically sealed, biocompatible housing implanted in the recipient. The electronic system, commonly referred to as a stimulator unit, essentially contains decoder and driver circuits for the stimulation electrodes. Acoustic sound reception and conversion of acoustic signals into electrical signals typically occurs in a sound processor typically worn by the recipient. The sound processor superimposes the preprocessed signals, properly coded, on a high frequency carrier signal which is transmitted transcutaneously to the stimulator unit through the closed skin. A sound input device such as a microphone converts ambient sound into representative electrical signals for processing by the sound processor. The sound input device is typically located outside of the recipient's body such as in a behind-the-ear housing worn on the auricle.
Traditionally, there has been interest in delivering a bioactive substance, pharmaceutical or chemical (collectively and generally referred to as a “drug” herein) in conjunction with implantable medical devices for a variety of purposes. For example, in one conventional approach an implantable medical device is coated with a drug. This and other conventional approaches typically require the incorporation of the drug into the implantable medical device during the manufacturing process of the device.